203 research outputs found
Polishing material removal correlation on PMMA – FEM simulation
The complexity of polishing is very high and experience in this field is required to achieve reproducible deterministic results concerning shape accuracy. The goal of this work is to predict the material removal of the polishing process on PMMA (Polymethylmethacrylate) using an industrial robot polisher. In order to predict the material removal, a FEM Model was created representing the polishing process. This model will help to predict the material removal when polishing parameters are changed. Experiments were carried out and compared to the results obtained from the different parameters tested in the simulation
Long-term changes in drought indices in eastern and central Europe
This study analyses long-term changes in drought indices (Standardised Precipitation Index—SPI, Standardised Precipitation–Evapotranspiration Index—SPEI) at 1 and 3 months scales at 182 stations in 11 central and eastern European countries during 1949–2018. For comparative purposes, the necessary atmospheric evaporative demand (AED) to obtain SPEI was calculated using two methods, Hargreaves-Samani (SPEIH) and Penman-Monteith (SPEIP). The results show some relevant changes and tendencies in the drought indices. Statistically significant increase in SPI and SPEI during the cold season (November–March), reflecting precipitation increase, was found in the northern part of the study region, in Estonia, Latvia, Lithuania, northern Belarus and northern Poland. In the rest of study domain, a weak and mostly insignificant decrease prevailed in winter. Summer season (June–August) is characterized by changes in the opposite sign. An increase was observed in the north, while a clear decrease in SPEI, reflecting a drying trend, was typical for the southern regions: the Czech Republic, Slovakia, Hungary, Romania, Moldova and southern Poland. A general drying tendency revealed also in April, which was statistically significant over a wide area in the Czech Republic and Poland. Increasing trends in SPI and SPEI for September and October were detected in Romania, Moldova and Hungary. The use of SPEI instead of SPI generally enhances drying trends
Three-gene predictor of clinical outcome for gastric cancer patients treated with chemotherapy
To identify transcriptional profiles predictive of the clinical benefit of cisplatin and fluorouracil (CF) chemotherapy to gastric cancer patients, endoscopic biopsy samples from 96 CF-treated metastatic gastric cancer patients were prospectively collected before therapy and analyzed using high-throughput transcriptional profiling and array comparative genomic hybridization. Transcriptional profiling identified 917 genes that are correlated with poor patient survival after CF at P<0.05 (poor prognosis signature), in which protein synthesis and DNA replication/recombination/repair functional categories are enriched. A survival risk predictor was then constructed using genes, which are included in the poor prognosis signature and are contained within identified genomic amplicons. The combined expression of three genes—MYC, EGFR and FGFR2—was an independent predictor for overall survival of 27 CF-treated patients in the validation set (adjusted P=0.017), and also for survival of 40 chemotherapy-treated gastric cancer patients in a published data set (adjusted P=0.026). Thus, combined expression of MYC, EGFR and FGFR2 is predictive of poor survival in CF-treated metastatic gastric cancer patients
Treatment and outcome of aquaporin-4 antibody-positive NMOSD: A multinational pediatric study
Objective To describe the clinical phenotypes, treatment response, and outcome of children with antibodies against aquaporin-4 (AQP4-Ab) neuromyelitis optica spectrum disorder (NMOSD).
Methods Retrospective, multicenter, and multinational study of patients with AQP4-Ab NMOSD aged <18 years at disease onset from a center in Brazil and 13 European centers. Data on demographics, clinical findings, and laboratory results were analyzed; calculation of annualized relapse rates (ARRs) pre- and on-treatment with disease-modifying therapies (DMTs) and of ORs for predictors of poor outcome was performed.
Results A total of 67 children were identified. At last follow-up (median 4 years, interquartile range 2–10 years), 37/67(57.8%) were found to have permanent disability. A more severe disease course was seen in the non-White ethnicity with both a shorter time to first relapse (p = 0.049) and a worse Expanded Disability Status Scale score at last follow-up (p = 0.008). The median ARR on treatment was 0.18 on azathioprine (n = 39, range 0–4), 0 on mycophenolate mofetil (n = 18, range 0–3), and 0 on rituximab (n = 29, range 0–2). No patient treated with rituximab as first-line therapy relapsed. Optic neuritis at onset was associated with a poor visual outcome below 20/200 (OR 8.669, 95% CI 1.764–42.616, p = 0.008), and a younger age at onset was associated with cognitive impairment (OR 0.786, 95% CI 0.644–0.959, p = 0.018).
Conclusions AQP4-Ab NMOSD in children is an aggressive disease with permanent disabilities observed in over half the cohort. All DMTs were associated with a reduction of ARR. First-line rituximab prevented further clinical relapses. International consensus on treatment protocols for children is required to reduce heterogeneity of treatment regimens used worldwide.
Classification of evidence This study provides Class IV evidence that for children with AQP4-Ab NMOSD, all DMTs, particularly first-line rituximab, reduced the ARR and prevented further clinical relapses
Tobacco use induces anti-apoptotic, proliferative patterns of gene expression in circulating leukocytes of Caucasian males
Abstract Background Strong epidemiologic evidence correlates tobacco use with a variety of serious adverse health effects, but the biological mechanisms that produce these effects remain elusive. Results We analyzed gene transcription data to identify expression spectra related to tobacco use in circulating leukocytes of 67 Caucasian male subjects. Levels of cotinine, a nicotine metabolite, were used as a surrogate marker for tobacco exposure. Significance Analysis of Microarray and Gene Set Analysis identified 109 genes in 16 gene sets whose transcription levels were differentially regulated by nicotine exposure. We subsequently analyzed this gene set by hyperclustering, a technique that allows the data to be clustered by both expression ratio and gene annotation (e.g. Gene Ontologies). Conclusion Our results demonstrate that tobacco use affects transcription of groups of genes that are involved in proliferation and apoptosis in circulating leukocytes. These transcriptional effects include a repertoire of transcriptional changes likely to increase the incidence of neoplasia through an altered expression of genes associated with transcription and signaling, interferon responses and repression of apoptotic pathways
Genomic and oncoproteomic advances in detection and treatment of colorectal cancer
<p>Abstract</p> <p>Aims</p> <p>We will examine the latest advances in genomic and proteomic laboratory technology. Through an extensive literature review we aim to critically appraise those studies which have utilized these latest technologies and ascertain their potential to identify clinically useful biomarkers.</p> <p>Methods</p> <p>An extensive review of the literature was carried out in both online medical journals and through the Royal College of Surgeons in Ireland library.</p> <p>Results</p> <p>Laboratory technology has advanced in the fields of genomics and oncoproteomics. Gene expression profiling with DNA microarray technology has allowed us to begin genetic profiling of colorectal cancer tissue. The response to chemotherapy can differ amongst individual tumors. For the first time researchers have begun to isolate and identify the genes responsible. New laboratory techniques allow us to isolate proteins preferentially expressed in colorectal cancer tissue. This could potentially lead to identification of a clinically useful protein biomarker in colorectal cancer screening and treatment.</p> <p>Conclusion</p> <p>If a set of discriminating genes could be used for characterization and prediction of chemotherapeutic response, an individualized tailored therapeutic regime could become the standard of care for those undergoing systemic treatment for colorectal cancer. New laboratory techniques of protein identification may eventually allow identification of a clinically useful biomarker that could be used for screening and treatment. At present however, both expression of different gene signatures and isolation of various protein peaks has been limited by study size. Independent multi-centre correlation of results with larger sample sizes is needed to allow translation into clinical practice.</p
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Northern Eurasia Future Initiative (NEFI): facing the challenges and pathways of global change in the 21st century
During the past several decades, the Earth system has changed significantly, especially across Northern Eurasia. Changes in the socio-economic conditions of the larger countries in the region have also resulted in a variety of regional environmental changes that can
have global consequences. The Northern Eurasia Future Initiative (NEFI) has been designed as an essential continuation of the Northern Eurasia Earth Science
Partnership Initiative (NEESPI), which was launched in 2004. NEESPI sought to elucidate all aspects of ongoing environmental change, to inform societies and, thus, to
better prepare societies for future developments. A key principle of NEFI is that these developments must now be secured through science-based strategies co-designed
with regional decision makers to lead their societies to prosperity in the face of environmental and institutional challenges. NEESPI scientific research, data, and
models have created a solid knowledge base to support the NEFI program. This paper presents the NEFI research vision consensus based on that knowledge. It provides the reader with samples of recent accomplishments in regional studies and formulates new NEFI science questions. To address these questions, nine research foci are identified and their selections are briefly justified. These foci include: warming of the Arctic; changing frequency, pattern, and intensity of extreme and inclement environmental conditions; retreat of the cryosphere; changes in terrestrial water cycles; changes in the biosphere; pressures on land-use; changes in infrastructure; societal actions in response to environmental change; and quantification of Northern Eurasia's role in the global Earth system. Powerful feedbacks between the Earth and human systems in Northern Eurasia (e.g., mega-fires, droughts, depletion of the cryosphere essential for water supply, retreat of sea ice) result from past and current human activities (e.g., large scale water withdrawals, land use and governance change) and
potentially restrict or provide new opportunities for future human activities. Therefore, we propose that Integrated Assessment Models are needed as the final stage of global
change assessment. The overarching goal of this NEFI modeling effort will enable evaluation of economic decisions in response to changing environmental conditions and justification of mitigation and adaptation efforts
Design of 3D Scene Scanner for Flat Surface Detection
There are number of plane detection techniques for a given 3D point cloud utilized in different applications. All of the methods measure planes quality by computing sum of square error for a fitted plane model but no one of techniques may count the number of planes in the point cloud. In this chapter we present new strategy for validating number of found planes in the 3D:point cloud by applied cluster validity indices. For a planes finding in point cloud we have engaged the RANdom SAmple Consensus (RANSAC) method to synthetic and real scanned data. The experimental results have shown that the cluster validity indices may help in tuning RANSAC parameters as well as in determination the number of planes in 3D data
Climate change and Lithuanian roads: impacts, vulnerability and adaptation
eISSN 2029-7092In Lithuania, like in other countries, climate change causes and will cause changes in natural and anthropogenic environment. The entire transport sector will be impacted, influencing the way it plans, designs, constructs and maintains infrastructure in the future. Roads are already sensitive to current climate variability. If today’s extreme weather events become both more frequent and extreme, so too will the level of disruption that they cause. Thus, roads must be adapted to changing climate conditions. The aim is to ensure resilience, to ensure that roads remain open under extreme weather conditions. The easiest and the most effective economically way is to implement adaptation measures for the new or reconstructed roads. But the existing older roads should be adapted also. The steps required to improve and maintain resilience of roads are definition of climate projections, identification of key roads and their vulnerability, identification and research on technologies for adaptation, preparation of methodologies, establishment of field operational trials. The aim of the research is to review Lithuanian roads in the context of climate change and its consequences. Methodology: climate and associated data collection and review, initial prognoses of the change (in short, medium and long term perspective) of meteorological elements, vulnerability assessment of the study area and the roads. Results: initial recommendations for adaptation action planningGamtos mokslų fakultetasVilniaus universitetasVytauto Didžiojo universiteta
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